Before daybreak for three mornings we drove out to the carcass. The ravens would arrive as first light washed over the snowy scene. They paid little attention to the camouflaged truck, but we had to sit perfectly still or they would detect our movement and fly off. The Vireo wolf had indeed found the carcass and was close by each morning, especially the last morning when his signal placed him in the trees right behind the carcass. Probably he had eaten his fill and was sleeping it off. Once, the ravens all went squawking up from the carcass, and we could see — and filmed — the Vireo wolf’s legs approaching from behind a big spruce. He stopped just short of the carcass, then retreated into the trees. To have lived so long in such dangerous surroundings required great stealth. Many people have glimpsed his legs in the film subsequently shown repeatedly on both TVO and the Discovery Channel.
That winter, 1994-95, back in the Vireo territory in the park, another pair of wolves capitalized on the pack’s absence and moved in. We had known about the trespassers since late January. One was Pretty 7, a young female collared the preceding May, who had wandered all summer in the northcentral part of the park near the Petawawa River and once outside the park almost to the Ottawa River. In early January, after travelling to the edge of the deer yard, she took up residence along the Bonnechere River in the north portion of the Vireo summer territory. We discovered one snowy afternoon in mid-March that she had a mate. Mary and I watched them run across a marsh less than 150 metres from the Vireo pack’s previous rendezvous site. We wondered what would happen when the Vireo pack returned.
To our surprise, it didn’t return. In early May 1995, long after all the other park wolves had gone back to the park, the Vireo wolf was still in the farmlands. Anxious to find out if he was alone again, Mary and I drove up a muddy road to his pack’s usual place. The calls of spring peepers cut the night air. His signal was loud when we got out of the truck to howl. A yippy wolf answered us, followed by long, deep howls on the same bearing as the signal. Then off to the right, about sixty metres from the Vireo wolf and partner, came distinctly coyote-like, nasal, treble yap-howls, accompanied by a lower-pitched, yippy voice. Four animals, as expected, but could the big Vireo wolf be mated to a coyote? Could the pack consist of both species?
We targeted the pack for capture, and over the next few weeks John Pisapio and assistants Alan Ramanus and Nadelle Flynn collared the three other pack members: a twenty-kilogram (forty-four-pound) lactating female, a slightly larger yearling female, and a more typical twenty-nine-kilogram (sixty-four-pound) young adult male. Like the howls we had heard, these weights suggested a mixed wolf-coyote pack.
The young adult male surprised us too. If our earlier interpretation had been correct and this Vireo pack had formed only the previous summer, that wolf should have been no older than a yearling. The explanation came a year later: genetics results confirmed that the young adult was not the big Vireo wolf’s son, nor was the yearling female his daughter. So, this could not be his pack of the previous summer.
What had happened? In the fall of 1994, he must have lost his new mate and two pups and again become a lone wolf. Then travelling to the farmlands as he had before, he must have joined this resident farmland pack. We called the farmland pack the Byers Creek pack, despite the big Vireo wolf’s presence in it.
In late May 1995, the Vireo wolf adopted a strangely ambivalent pattern of movement. Repeatedly, one day he was with his farmland family, and a day or two later was back on his territory in the park. Each time he made the switch, he had to travel through another pack’s territory. He seemed torn between his new pack and his old lands.
We wondered if he could be a member of two packs. He always travelled back to the mid- and southern section of his lands near Vireo, Robitaille, or Wilkins lakes, a difficult area for us to access. However, we managed to get close enough to howl at him a few times and confirmed with howling and tracks that he was alone.
Meanwhile, trespassing Pretty 7 and her mate denned in an old clearing beside the Bonnechere River, the northern part of the Vireo territory. They used a sandy embankment that had been excavated more than a century before to form the cellar of a roadhouse. Mary and I kept signal-watch on this fledgling pack. Rarely was Pretty 7 more than a hundred metres from her den. In early July she moved her pups two kilometres west across the Bonnechere River.
One hot July evening, wanting to check on her, we hiked the north shore of the river. Mosquitoes carried us along. After a while Mary turned on the receiver and, to our consternation, Pretty 7’s signal came in on mortality mode. What could have happened? Could the Vireo male have come back into this northern sector of his territory? We changed channels and, sure enough, for the first time that summer he was up there.
It was dark by the time we managed to ford the river at a rapids. By flashlight we followed a game trail along the south shore, but soon a complex of beaver ponds blocked us. After groping around in the alders awhile, we were forced to return to the truck and camp for the night.
The next morning we set off early, this time working our way around the ponds and following the signal to the Pretty wolf’s rendezvous site. It was at a recently drained beaver pond with new grasses and sedges just starting up. We tracked the signal to a high- and-dry beaver lodge and for a while could not find the collar. Finally, Mary bent over, looked inside the old lodge through a tunnel entrance and saw it lying on the central platform within. Only the collar was there, still bolted up. No blood was on it, no matted hair, but a pair of chip marks along its edges showed where wolf teeth had clamped down on it.
There were no signs of a struggle around the lodge. Fresh pup and adult tracks plastered the mud, but nothing more. For hours we combed the area, searching in increasingly larger circles from the lodge, finding only scats and bones of beaver and deer.
The collar could have come off in a fight, or even in play, but if it were that loose she would have lost it within the first few days after collaring. All other times we retrieved wolfless collars worn for more than a few days, we were able to confirm that the wolf had died. Pretty 7 had worn her’s for fourteen months. She was alive when found from the air nine days earlier. If she had been killed just after that, enough time would have elapsed in the summer heat for decay organisms and scavengers to separate her head from her body. How her collar got into the beaver lodge, a large enough entrance for a pup to carry it in, or a fisher or fox, but not an adult wolf, remains a mystery.
The Vireo wolf became the prime suspect. After all, Pretty 7 and her mate had been trespassing, even trying to raise pups on his land. Also implicating him was a change in his pattern of movements. After that, never again did he go back to his farmland family, the Byers Creek pack. He simply deserted them and stayed on his old territory, now using this northern sector that he had not used previously. He even pushed beyond his boundaries, first to the east to within a few hundred metres of the Basin Depot wolves, then a few days later to the west, where he was equally close to a male in the Redpole Lake pack. Perhaps he was looking for scavenging opportunities again.
In August we laid on a few extra flights, anticipating that he would get killed by an adjacent pack, or even possibly by the Pretty female’s mate if he was still there. Back in the farmlands, John occasionally heard the Byers Creek pack howl and suspected it consisted of six animals, not just the remaining three. Had the big Vireo wolf been ousted?
He must have died in early September, judging by the leaves partially covering his skeleton. Scavenger beetles, bacteria, and flies had completely cleaned his skull. We had an incisor tooth aged by its annular rings. He had lived ten years, making him the second oldest wolf in our study.
His large skull now sits on the window shelf in my office, grimacing down at me, the mystery of his life gone from the empty braincase. At times I look at it and think about wolf social order. On a genealogy chart drawn by geneticists Sonya Grewal and Paul Wilson is the near-irrefutable evidence that the denning Pretty Lake female, the one that all our circumstantial evidenc
e suggests was killed by the big Vireo wolf, was his daughter.
Reinterpreting, Pretty 7, daughter of the Vireo wolf, had been caught and collared on a dispersal foray looking for a mate, which explains her extensive movements that summer. Eventually she returned to her natal territory with her new mate, found it empty, for reasons unknown, and settled down.
Maybe the Vireo wolf attacked her mate and she joined in. Or perhaps she attacked her father and lost, or her mate attacked him and she was forced to choose which wolf to be loyal to, father or mate — we will never know. The event remains a secret locked up in the forest.
Hybridization is treated largely as a biological mistake in ecology texts. We learn about the immutability of species, about barriers that exist to prevent closely related species from interbreeding, and that hybridization normally results in biological failure. Most often, hybrids have little vigour, or are sterile, or produce sterile offspring.
Yet, recent research is emphasizing that across the span of evolution, hybridization has been a major source of genetic variation contributing in a major way to the diversity of life on Earth. It is one important way that species innovate, fabricate, adapt.
Our experience with the Vireo wolf and the Byers Creek pack made us ask to what extent coyote genes may be infiltrating into the Algonquin Park wolf population. Not only was that question important, it led to some exciting and unexpected discoveries, to no less than a redefinition of the species we were studying.
Genetics research done in Robert Wayne’s Californian lab laid the necessary foundation. He and co-workers found that wolves in eastern North America showed a preponderance of coyote-like DNA in their mitochondria. Mitochondria are tiny bodies important in cellular metabolism found in cells of the body, and they contain DNA. Unlike other DNA found in the nucleus of cells, however, this mitochondrial DNA is cloned by the mother and passed to her offspring. The mitochondrial DNA in the father is not inherited. So by finding coyote-like mitochondrial DNA in wolves, the Californian research group concluded that female coyotes were mating with male wolves. The reverse — male coyotes mating with female wolves — was not happening or not detectable. Perhaps a female wolf would be less likely to choose a small, coyote-like animal for a mate.
The Californian group published the frequency of alleles at a certain group of gene loci, or locations on the chromosome, in both wolves and coyotes from a wide variety of places in North America. Alleles are different forms of a gene, and at the loci studied, any one of up to ten different alleles are possible. Obviously, wolves and coyotes share most of their genetic material; after all, humans and chimpanzees share 98 per cent of theirs. However, the frequencies with which various alleles show up in populations of even the same species differ and there also will be some species-specific alleles.
We established a partnership with geneticist Brad White and colleagues at McMaster University in Hamilton, Ontario, to examine our stockpile of blood taken from each wolf when we collared it, and muscle tissue collected when wolves were autopsied at the University of Guelph. Paul Wilson and Sonya Grewal, with the help of a few others, spent long hours in the lab extracting the DNA from blood or tissue of Algonquin wolves, then amplifying and teasing it out to allow identification of the alleles present at sixteen loci.
The results surprised us, even though we were forewarned by the Californian work. Thirteen per cent of the Algonquin Park wolves carried at least one coyote-specific allele, that is, an allele found only in coyote and not in any wolf populations surveyed in North America. Twenty per cent carried wolf-specific alleles. The Algonquin wolf population, then, has experienced hybridization.
Brad does not like to rest genetic evidence on species-specific alleles alone, because if he were to test more populations, they may turn out not to be unique. Geneticists have a way of illustrating similarities among populations called a “genetic tree,” based upon comparing the frequencies of all the alleles they sample. The length of the lines between populations, or the limbs of the tree, show how closely populations or species are related. Such a tree, even more than the unique alleles, allows them to show evolutionary lineages forged over the millennia.
The genetic tree Paul and Sonya worked out included the placement of other wolf and coyote populations studied in Wayne’s lab, and showed three distinct groupings: wolf, coyote, and hybridizing wolf populations. The Algonquin Park wolf fell into the latter grouping, with southern Quebec wolves and the southeastern United States red wolf. The red wolf (Canis rufus), considered a different species, was most similar genetically to Algonquin Park wolves. All three of these populations were closely grouped and distinctly different from other wolves and coyotes.
Notwithstanding the presence of coyote alleles, the Algonquin canids we have been studying are clearly more similar to wolves than coyotes. Like wolves, they eat almost exclusively large mammals rather than mice and hares. Like wolves, they kill beaver, which are almost completely ignored or too difficult for coyotes. The body weights of the Algonquin canids are, on average, much too large for coyotes, though some fall within a range of overlap. The territories of the Algonquin canids are like typical wolves, six or more times larger than those of coyotes. Pack sizes are more wolf-sized than coyote-sized in those that escaped exploitation long enough — twelve to fourteen animals in two cases. We recorded no yearling breeding, which often occurs among coyotes. Algonquin howls resonate from deep wolf chests and are not yippy and nasal like those of coyotes.
Clearly, the introgression of coyote alleles in general has not made the Algonquin population intermediate between wolf and coyote either physically or ecologically. Not yet, anyway. The loci studied, while indicative of hybridization, are largely from nonfunctional parts of the chromosome, conveying no specific traits.
However, one physical and two behavioural features of Algonquin wolves nagged at us as possibly influenced by recent coyote hybridization. The high degree of social acceptance without aggression between non-pack members is more coyote-like than wolf-like, though more likely it is a result of prey abundance, as discussed in the previous chapter. Also more typical of coyote behaviour is the unusually common split-pack hunting rather than whole packs hunting together, but this trait shows up in red wolves too, making interpretation difficult. Brad thinks that the degree of hybridization found genetically in the Algonquin Park wolves is not sufficient to be the cause of these behavioural characteristics.
More substantive evidence of possible coyote influence was found from skull measurements of Algonquin Park wolves made by student Sarah Stewart. She used a standard set of ten measurements and compared them with published measurements of skulls from Algonquin and vicinity all collected at least thirty years previously. The skulls in our collection turned out to be statistically smaller — not much, but smaller.
Could recent coyote gene swamping be changing the characteristics of the Algonquin wolf? There is no other apparent reason for these smaller skulls. Undoubtedly the invasion of coyote genes into Algonquin Park is influenced by opportunity. Immediately adjacent to the east and south sides of Algonquin Park during much of the breeding season, park wolves, including packless singles, encounter coyote-like animals in the resident packs. Any interbreeding with these animals carries additional coyote genes into the park.
There may be another, equally threatening way that coyote genes get into Algonquin Park wolves. Coyote-like animals may invade.
McDonald 2 Wilno, a young male captured in the summer of 1993, may have been predominantly a coyote. He weighed only twenty kilograms (forty-four pounds). Because he was caught well inside the park, initially we assigned him the name McDonald after the pack that had lived there, even though it had been annihilated down in the farmlands the previous winter. At that time we were still looking for survivors.
After a while it became apparent that he was not a McDonald Creek wolf; he was a farmland animal and had been captured on a dispersal foray. Two weeks later he settled down in mixed forest-farmland south
of the town of Wilno. Over the next four years, summer and winter, we tracked him behind estate housing, at the back of farmers’ fields, along busy Highway 60, and east to open lands around the “German Settlement.” Once, just beyond the last house, he came up the road to our howls, crossed the ditch, circled us through a dark field, and continued along the road almost to the streetlights. Another time he was on the very edge of the bustling town of Barry’s Bay.
His territory was long and thin, and only thirty-four square kilometres in area, more coyote size than wolf size. Mostly he was alone, occasionally with a mate. Their howls both sounded coyote-like. John Pisapio found their den one year, but we never confirmed pups.
Then there was Mathews 9, a tiny, fourteen-kilogram (thirty-one-pound) lactating female collared in 1994. She was caught in the interstice between two newly formed packs: Hardwood Lake to the west and Military to the east, in an area still undergoing wolf reshuffling after the loss of the Mathews pack one and a half years earlier. Her life fit no pattern. We could pinpoint no den; she must have lost her pups. In the winter she travelled widely in the Round Lake deer yard, mostly with one other animal, often trespassing in the resident Byers Creek pack’s territory. Once, she shared a deer carcass with two wolves from the Hardwood Lake pack. Twice, she made forays back into the park, both times into the Hardwood Lake territory. Strangely, both times, McDonald 1 Hardwood made the trip back too, but separately. They were not found closer than 1.5 kilometres. Both times she returned to the farmlands within a day, but he stayed on.
Even stranger was that on the second of these forays, she was with McDonald 2 Wilno. Two of the smallest animals were travelling together. They met on March 5 when both were trespassing on Byers Creek land. Ten days later they were still together, thirty-five kilometres inside the park, and two days later were back in the Byers Creek territory where they stayed for four days. Then the Wilno wolf left her and returned to his own land.
Wolf Country Page 28